A cylindrical photosensitive member as used in a copying machine is mounted on or dismounted from a support or center shaft which is fixedly mounted on the frame of the machine by an axial movement for purpose of replacement, maintenance or inspection.
Generally, a cylindrical photosensitive member is open at at least one end thereof because of its manufacturing limitation, and such opening is closed by an end plate only after the photosensitive member is brought to its normal mounting position on a support shaft, thereby preventing a misalignment and providing a reliable support. Accordingly, in the course of mounting the cylindrical photosensitive member on the support shaft or dismounting it from the latter, there is a high likelihood that the photosensitive member may be misaligned with respect to the support shaft. As is well known, the photosensitive member carries a vulnerable photosensitive layer as may be formed with selenium, on its outer periphery, and the photosensitive member is mounted in a surrounding environment which contains a charger, developing unit, neutralizer and the like. Hence if the photosensitive member is misaligned during its mounting or dismounting process, a contact thereof with the surrounding units may cause a damage to the photosensitive layer.
Accordingly, a variety of guiding apparatus have been proposed in the prior art for guiding the photosensitive member in the axial direction without causing any misalignment during the mounting or dismounting thereof. Such apparatus may be assembled into a copying machine or may be separate from the latter.
For a guiding apparatus which is to be assembled into a copying machine, there is a disadvantage that it must occupy a certain space which may be utilized for other devices. For a guiding apparatus which is separate from a copying machine, the apparatus must be attached to the machine as required. This results in a degraded quality of maintenance and disadvantageously requires a special space for its stowage when not in use.